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The ALFA-Elite
TSD Rally Computer
CONTENTS:
Introduction
Software:
Technical Specifications:
Installation:
Mounting:
Wiring:
A Little About Sending Units:
Mounting your ALFA sending unit:
Description of your ALFA:
Controls:
Displays:
Power On Test and Customization:
Rally Operation:
General:
Odometer:
Factor:
CAS changes:
Computer time clock:
Real time clock:
Appendix A: Differences between Elite and TSD
Appendix B: Care and Feeding of Liquid Crystal displays:
Appendix C: Software revision history
Warranty:
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INTRODUCTION:
The ALFA-tsd rally computer represents the latest technology available for rallying. As a navigational aid, the ALFA-tsd should provide you with a significant advantage over your competition. As with all ALFA rally products, the ALFA-tsd is a breakthrough in price as well as performance.
Some of the special features of your ALFA-tsd include:
Backlit Liquid Crystal Display.
User friendly (guess free) data entry system.
Clock in 12 or 24 hour time.
Timing in seconds or hundredths.
Overall, incremental, and countdown odometers.
Distance and Time measured to hundredths or thousandths.
Dual sending unit inputs with separate factors.
Drivers display with "Null" error, odometer, and CAS.
On-the-fly timing and odometer corrections.
Advanced error correcting and timing features.
Reliable operation backed up by a one year parts and labor warranty.
A NOTE ABOUT QUALITY:
All ALFA rally products are hand made. We like to think that this lends them a certain amount of character. What this really means is that, like snowflakes, no two ALFAs are exactly alike. It is possible (indeed likely) to find fingerprints, smudges, etc., that were missed during the final inspection before your unit was shipped to you.
Despite the above cosmetics, it is important to realize that the electronics inside your ALFA are built to highly exacting, state of the art, standards. Each unit is fully tested, calibrated, and then tested again to insure reliability.
We hope that you will be pleased with your new ALFA-tsd computer. We are always receptive to phone calls, and letters with suggestions for improvement to our products. In addition, if any software improvements or upgrades become available while you own your ALFA-tsd, you will be offered the opportunity to upgrade for little or no cost (usually just shipping and handling charges).
SOFTWARE:
The software revision of your computer is the first two digits of your serial number, visible when you first power on the ALFA-tsd. There are many new features in the works, and several being tested right now, which will be supplied to you at nominal cost when available. It is the policy of Small Systems Specialists to not release any software which has not been "Rally Tested" first. The original software shipped with ALFA-tsd computers saw many thousands of miles of RALLY USE, including a victory at the MGCC's International 1000 rally in August, 1987, before it was considered "Rally Tested". Your software (Revision 3 as of this printing) was tested and proven in a similar fashion by Small Systems Specialists, as well as independent testers before it's release.
TECHNICAL SPECIFICATIONS:
This information is included for the technically curious and otherwise insane. It is not necessary to either read or understand this page in order to operated your new ALFA-tsd to it's best advantage.
Processor: 84C00 CMOS microprocessor.
RAM memory: 6116 (2k), 150ns CMOS static. (Elite: MK48Z02 NVRAM)
PROM: 2764 (8k).
Clock: 5369. Drives processor and RTC.
Display: Liquid Crystal, Super-twisted. Character height 9mm. 2 lines of 16 characters.
Backlight: Diffuse array of LED elements, Life expectancy 100,000 hours .
Software: Software is written entirely in Z-80 assembly language **.
Sending units: Supplied sending units are magnetically operated "Hall Effect" non-mechanical switches. The input to the computer is standard TTL (+5v, negative edge triggered) pulled up through 2200 ohms.
** Full source code and all of the tools to assemble the ROM may be obtained for $10,000 (no joke). Contact Small Systems Specialists for details.
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INSTALLATION:
MOUNTING:
The ALFA-tsd is light weight and easily mounted with heavy duty velcro (not supplied). Clean both the dashboard and the ALFA-tsd with alcohol or other solvent before attempting to stick on the fasteners. If the dashboard has any grease or other contaminant (especially vinyl conditioners of any type) the adhesive will not work properly. It is advisable to mount the ALFA-tsd on a flat surface to maximize the working area of the fasteners.
The ALFA-tsd may be mounted on it's back or bottom depending upon your car's dashboard configuration. For best display visibility, the ALFA-tsd's front panel should be tipped back just beyond square from the operators line of sight (see illustration). It is important to mount the ALFA-tsd firmly to the dashboard. If the ALFA-tsd is not well attached it may become a safety hazard to the occupants of the car. Additionally, a loosely mounted ALFA-tsd tends to transmit more of the cars vibration to the electronic components and will adversely effect reliability.
The drivers display is mounted similarly to the main unit. Please observe the same instructions regarding viewing angle and security of mounting.
If a rigid mounting is preferred, there is an empty space on both edges of the computer where mounting bolts may be securely attached. The only access to the inside of the ALFA-tsd is by removing the front panel. If you do not feel comfortable working around microelectronic components in cramped quarters, please do not attempt this. See your warranty for liability assumed upon opening the ALFA-tsd's enclosure.
If the LCD displays reflect in your windshield, you may want to fashion a shade to go over the top of the ALFA-tsd. Use heavy black paper or light cardboard to make the shade. DO NOT USE METAL OR OTHER RIGID MATERIAL or a safety hazard will result in the event of an accident.
WIRING:
Your ALFA-tsd computer must be attached to your car's electrical system. A six position terminal block is provided to make connections as easy as possible. In addition, quick disconnect connectors are employed to allow rapid removal of both the ALFA-tsd and the drivers display without having to remove any wiring.
As shown in the illustration, the wiring harness has 3 connection points. There are two 25 pin "D" connectors, one for the driver's display and one for the main computer. These connectors are keyed so it is impossible to interchange the ends accidentally. Do not force the connector into it's receptacle, a gentle rocking motion will fit the ends together if the connector's fit is tight. You may twist or fold the ribbon cable in order to route it neatly, but do not crease it. If the ribbon cable is creased, the wires may fatigue prematurely. The terminal block is usually mounted underneath your dashboard in a position convenient to your power wires.
There are 9 wires leading from the main computer to the terminal block, but only 6 connections are required because the power and ground wires are doubled up. The cable supplied is pre-attached to the terminal block, please refer to the illustration for the names of the connections. The screw heads of the terminal block are color coded to aid you during the wiring process. Use great care if you need to extend the ribbon cable, interchanging connections will cause permanent damage to your ALFA-tsd's computerized circuitry.
The following describes how and where to attach each connection. Use only 18 gauge or larger copper stranded wire to make each connection. To insure a secure connection to the terminal block, strip about 1/2 inch of insulation carefully from the end of the wire, then twist all of the loose strands tightly together. If you use a knife or razor blade to strip the wire, be careful not to nick the wire when removing the insulation or a weak mechanical connection will result (and usually fail at the worst possible time!). Next, wrap the wire clockwise around the screw and screw it snugly to the block. Remove any excess wire extending beyond the screw to prevent short circuits. After all the wires have been connected, it is a good idea to put a piece of vinyl electrical tape over the entire block so that you will not accidentally short any of the screws at a later time.
MAKE SURE YOUR ALFA-tsd IS TURNED OFF BEFORE PROCEEDING!
POWER WIRE: The first connection is for the power which operates your ALFA-tsd computer. This is the first (red colored) screw on the terminal block. This should be connected to a source of +12 volt (9-15 volts is OK, most cars run at 13.5 volts) power which is unaffected by your cars ignition switch (it is undesirable for power to shut off while parked or while starting your engine). The dome light fuse or horn fuse is usually a good connection point. Make sure that you attach to the fused side of the circuit so that your ALFA-tsd will be protected by the fuse. The BEST place to connect power is directly to the positive terminal of the car's battery. If you use the direct battery connection, be sure to insert a 1 amp fuse into the power wire to protect your ALFA-tsd. The ALFA-tsd has no internal fuse, it must be protected by your car's fuse box or one that you install yourself!
GROUND WIRE: The ground is the third screw in the terminal block (painted black), but should be attached at this time before connecting the sending unit(s). The ground wire may be attached to the chassis of your car, or directly to the negative terminal of your battery. Do NOT attach the ground to a screw holding interior trim or dashboard parts, this is usually not a good electrical ground. If you used the direct battery connection for power, it is usually best to connect the ground directly to the battery as well. Ideally, you can use a piece of shielded coaxial cable (such as cable-tv lead wire) for the power/ground connection in order to minimize electrical noise form the cars ignition system which could cause odometer inaccuracy.
(At this point you may turn on the power switch and test that the unit is functioning. See the OPERATIONS section for details of this operation. Turn the ALFA-tsd back to the OFF position before continuing.)
The BLACK lead from the sending unit is attached to the same ground screw as the ground wire from the car. Do not attach the sending unit BLACK wire to any other ground point in the car or a noise problem (known as a ground loop) will occur causing your odometer to be inaccurate.
+5 VOLT WIRE: This wire supplies a source of regulated power to the sending units. It is connected to the RED or ORANGE lead from the sending unit. The second terminal block screw (yellow) is the 5 volt connection.
A and B WIRES: These wires are the sending unit pulse inputs. If you intend to use only one sending unit you may attach these two wires together to allow the ALFA-tsd's A-B sending unit switch to act as a factor switch for a single sending unit. The output lead from the sending unit is the GREEN wire, and the terminal block screws for these connections are painted green.
REMOTE HOLD: If you ordered your ALFA-tsd with the optional remote HOLD button, it is wired to the HOLD terminal and to the ground terminal. The hold terminal is the sixth (blue) screw on the terminal block.
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A LITTLE ABOUT SENDING UNITS:
The function of a sending unit (also known as an impulse unit) is to transmit wheel rotation to the ALFA-tsd's computer so that it can accurately measure the distance traveled. There are several types of sending units available on the market, all having different advantages and disadvantages.
The Hall Effect sending units supplied with your ALFA-tsd are mounted at the wheel with magnets in the rims. Alternatively, the magnets may be attached to the back of the wheel hub, or inside a brake drum. The advantages of the Hall Effect sending unit are higher speed capability and insensitivity to vibration. These units are usually mounted on a non-driven wheel for greater accuracy.
Sending units are available from some sources which attach in-line with your odometer cable. Some attach at the transmission, some behind the dashboard, and other require that you actually cut your speedometer cable and splice in the sender! The primary advantage of this type of sending unit is ease of installation, however this is offset by mileage inaccuracies caused by wheel spin during acceleration. Some sending units are available which attach to your hubcap or under your wheel mounting bolts. These sending units have the advantage of being portable and quick to install, but they are vonerable to attack from rocks and tree limbs frequently found on rally roads. Most of these sending units are compatible with your ALFA-tsd, but some are not.
Many ralliests have had good success using the cruise control or ABS brake sensors already installed in their cars. We do not recommend using these, because the interaction between the cars electronics and the ALFA's are not predictable, and damage to either may occur. Please contact Small Systems Specialists before attempting to use any non-standard sending unit.
Sending units known not to work well with the ALFA-tsd are older photo-electric sending units from Chronar or Zeron, and the non-magnetic proximity probe from Terra-trip. Note that some of the photo-electric units do work well, but the power requirements for these units vary.
MOUNTING YOUR ALFA SENDING UNIT:
Mounting the sending unit is different for every car, and requires some imagination. If you do not feel comfortable with the mechanics involved, please refer to the above discussion on sending units and purchase one of the fine, easy to install (speedometer cable or hubcap mounted) sending units described.
The ALFA sending unit works best when mounted on a non-driven wheel (rear wheel for front drive cars, front wheel for rear drive cars). If your car is equipped with disk brakes, the back side of the dust shield makes an excellent mount. If your car is equipped with drum brakes, you may need to build a small bracket to hold the sending unit close enough to the wheel to sense the magnets. In either case the sending unit should be mounted at the highest possible location to minimize it's chances of being hit by a rock kicked up from the wheel (see illustration). The sending unit may also be attached to a strut or any other part of the car that maintains it's distance from the rotating wheel. For maximum protection of the sending unit, the magnets may be mounted inside the drum, or on the back of the wheel mount studs. The sending unit would be mounted directly to the brake assembly, where is is shielded from rocks and other road debris. A possible alternative to wheel mounting would be mounting the magnets to the cars drive shaft and the sending unit to either the transmission or axle casing.
The magnets are mounted to the wheel or hub with the white mark facing toward the sending unit. You may use magnets other than the ones provided with your ALFA, but they must be oriented with the south pole of the magnet facing the sending unit. Ceramic magnets are supplied with your sending unit, they are inexpensive, of average power and should allow a gap of about 1/8 inch between the sending unit and the magnet. More powerful "rare earth" magnets may be used and may in some cases provide gaps up to 1/2 inch.
Be careful to protect the wires attached to the sending unit from the weather by wrapping the splices fully with vinyl tape. All splices in the wiring should be soldered. The best way to route the wires from the wheel is to attach them to the brake hydraulic line with nylon cable ties. The brake line is usually routed such that it will not be stressed as the suspension does it's job, and also is least prone to breakage from road hazards. The wire should enter the inside of the car at the earliest possible point, and care should be taken to be sure that it is not crimped at the point of entry. The length of all wires associated with the sending units should be kept as short as possible and should not be routed near ANY ignition components. Three conductor stranded, shielded, microphone cable makes an excellent sending unit leadin. The shield should be grounded at one end only to prevent noise pickup.
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OPERATION OF YOUR ALFA:
DESCRIPTION OF CONTROLS: (Refer to the illustration for the location of the controls described.)
MAIN CONNECTOR: This connector attaches the driver's display, the sending units, and the power required to operate your ALFA-tsd computer.
A/B SWITCH: If you have two sending units this switch allows you to easily select which sending unit you are using. Each sending unit has a separate odometer correction factor which is selected at the same time as the sending unit. If you have only one sending unit, and have wired both inputs together (see installation section) this switch will still select one of two preprogrammed factors. This is useful for situations where the rallymasters factor seems to change between different road surfaces.
KEYBOARD: The keyboard is used to enter mileage and time information into the computer. The bottom two rows of keys are increment/decrement buttons used to "dial up" the required value. The ENT key is used to ENTER the value once you are sure it is correct. The CLR key clears the value to the default setting for the function selected, and the SEL key is used to select different options as described in the operation section of this manual. The CAS key is used to exchange the CURRENT CAS and the NEXT CAS.
HOLD BUTTON: The hold button freezes the display without disturbing the operation of the computer. This is useful for logging course information. After the HOLD button is released, the held reading may be recalled by pressing the right-most up and down arrow buttons together. Note that Recalled mileage displays thousandths of a mile even if that mode is not selected. The drivers display is not affected by the hold button, this allows the navigator to log information while the driver maintains the course.
FORWARD/PARK/REVERSE SWITCH: This switch causes the odometer and computed time to run either forward or reverse. In the center, or PARK, position the odometer is effectively disconnected from the wheels. Time related functions are still active even when the odometer is parked.
When the ALFA-tsd is in either PARK or REVERSE, the beeper (if equipped) sounds every 16 hundredths (or seconds) as a reminder.
FUNCTION SELECTOR: The function selector is used to determine what type of data is being entered into the computer. The RUN position is the normal position for this switch so that no erroneous data is entered into the computer. Each function selector position is covered in detail in the rally operations section of this manual.
POWER/CONTRAST SWITCH: This rotating switch works like the volume control on a radio. Clockwise rotation turns the ALFA-tsd on and adjusts the contrast of the liquid crystal display. The knob must be rotated more than half way around before the display is visible. This is deliberate, to prevent accidentally turning the ALFA-tsd off while adjusting the display.
DRIVERS BUTTON: Pressing the button on the drivers display causes the incremental odometer to rezero and to be displayed in the distance position of the display. Pressing the button again causes the distance display to return to official course mileage.
Displays:
When in the RUN mode, the main computer display consists of four displays:
The upper left display is the odometer. Distance is measured to 1/1000 of a mile (or kilometer) and displayed to your choice of 1/100 or 1/000 miles.
The lower left is the active CAS and the NEXT CAS (NEXT CAS is displayed in braces). Computed time is always calculated based upon the active CAS. Only the whole part of the CAS is displayed for clarity, note that CAS is entered AND COMPUTED to 4 digits (2 places to the right of the decimal point).
The upper right display is the real time (time-of-day) clock. Time is displayed to your choice of seconds or 1/100 minutes.
The lower right display is the computer time clock displayed to the same units as the real time clock. Computed time is the time it should be traveling over the course at the specified CAS. When computed time and real time agree, you are on time (zero score!).
While in the RUN mode, pressing the ENT key will switch the displays to a higher precision mode. During this mode the mileage, time, and cas will be displayed to 1/1000 (1/10 seconds) regardless of the ALFA's normal mode. Press ENT again to return the display to normal.
The drivers display is split into three sections:
The left half of the display is the "NULL" readout. This is the difference between the real and computed time clocks, displayed in either seconds or 1/100 minutes. It is the drivers task to keep the null on 00.00. If the driver is going too fast the display will indicate a positive number and the message "AHEAD" will appear below the number. If the driver is driving too slowly, the number will be negative and the message "BEHIND" will appear.
When the car is within a few hundredths of the correct time, the null displays in thousandths to allow the driver to "fine tune" the car to an exact zero. In addition, the ahead/behind message is replaced by an "analog zero meter", which you simply keep centered to score a zero.
The upper right display is the drivers odometer. Normally this odometer echoes the navigators odometer, but the driver may elect to display an incremental distance by pressing the drivers button (see above). When in incremental mode, an asterisk (*) will appear preceding the odometer. If the navigator has entered a distance alarm (see rally operation section ) the drivers odometer will count backwards until zero. The display will blink "BEEP BEEP" (and the beeper will sound, if so equipped) for .2 miles before the alarm mileage is reached. The navigator may eliminate the beep by either entering or clearing a new alarm setting, or by simply pressing CLR while in the run mode. In countdown mode an angle bracket (>) will precede the odometer.
The lower right display is the CAS that the driver is supposed to be maintaining. This saves the navigators left ribs from the constant "what's the CAS supposed to be" nudge from the driver. If selected, the speedometer is displayed next to the CAS. Note that the speedometer is a low priority item for the ALFA and may appear jumpy from time to time while the computer does more important things.
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Power On Test and Customization:
To turn on the ALFA-tsd, rotate the power/contrast switch clockwise and adjust the knob for a comfortable viewing contrast. A sign-on message, "Test in progress", should appear with the serial number of your unit. If this message does not appear, adjust the contrast control until it is visible. If there is still no message, turn the unit off for 10 seconds and try again. If the unit still fails, make sure that you have power applied, and that all of the connectors are firmly plugged in.
If your unit is equipped with the non-volitile memory option, the power on test and customization is skipped, and the last used setup is maintained along with the mileage, factor, CAS, and computed time. The time of day clock is not maintained during power down, and therefore is reset every time power is turned on. To force the ALFA-tsd to perform the power on test and reset all of the customized options, hold the CLR key while turning on the power switch.
ALFA-tsd's equipped with revision 3 software will operate without the drivers display attached. If you desire to do this, turn off the unit before either removing or installing the drivers display. Software prior to revision 3 requires that the drivers display be attached for the ALFA-tsd to operate.
The power on test will continue for several seconds. If an error is reported, or he test does not conclude, cycle the power as described above. If the unit still reports an error, please call Small Systems Specialists for assistance.
After the test is finished, you may customize the ALFA-tsd as prompted on the navigators display. The leftmost UP and DOWN arrows on the keyboard select the corresponding upper and lower selections on the display.
Your choices include:
Timing in hundredths of a minute or seconds.
Precision displayed to 1/100 or 1/1000 miles.
12 or 24 hour clock format.
Display speedometer
Clear on enter
If you select the default setting you will get time and distance to 1/100, and a 12 hour format clock. If you wait more than 10 seconds to make a selection, the defaults will automatically be chosen.
You may alter the customization of your ALFA-tsd at any time while in the RUN mode by pressing the lower left and lower right arrow keys together. Selecting the default at this time will simply return to rally mode without making any changes, otherwise you may select new options as usual. Please note that changing the time format may cause the clock to become inaccurate. If you change the time format (other than simply turning off or on the hours) reset the clock before continuing the rally!
Note: If the HOLD button had been pressed while the ALFA was off, the display may appear blank or incomplete after the customizing procedure is complete. If this is the case, simply press the HOLD button to start the computer working. If you have a remote hold switch attached to your computer, it may need to be released too.
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RALLY OPERATION:
The computer's function during a rally is to measure time speed and distance (thus the name "tsd"). The navigator enters the CAS into the computer and the starting time of each leg of the rally. As the car is driven the computer calculates how long it should have taken to drive to where you are. It compares this time to the actual time it took to drive the distance and displays the error (difference) on the drivers display. These calculations occur several hundred times each second, and provide continuous readout on the displays. The function knob allows the navigator to enter and correct these time and distance measurements so that the driver can always stay on time. Normally the function knob is left in the RUN position. The RUN position locks out all of the keys on the keyboard (except CAS and ENT) so that you cannot make any accidental entries.
As you move the function knob (gently) to each position, the selected function is displayed, in English, on the bottom line of the navigators display. To enter a value you use the up/down arrow keys which correspond to each digit until the desired value is displayed. Then press the ENT key to transfer the value to the computer. Once entered, a confirmation message is displayed, and the keyboard is locked out from further changes until the function knob is moved to a different position.
If not entered, the set values are held for each function. This allows you to preset several values which must be entered at one time, and then quickly enter all of them. For example: You have to restart at a stop sign, and you want to do this as quickly as possible. You can select CTC, preset it's value, then select 0D0 and preset it's value. Upon arrival at the stop sign, just quickly move the function knob to ODO, press ENT, move to CTC, press ENT. All done in 2 seconds or less!
The HOLD button freezes the navigator's displays for hacking and/or logging purposes. Press the HOLD button once to freeze the display, press it again to release the display. It is important to note that ALL computer operations continue normally, only the display is held, also the driver's display never holds. It is important for the driver to have continuous information. After releasing the HOLD, you may recall the information which was displayed by pressing the rightmost two arrow buttons at the same time. The hold recall value will include the thousandths of a mile digit, even if it was not displayed at the time of the hold.
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In order to properly follow the rally course, it is important to have an accurate odometer. The ALFA-tsd's odometer display counts from 000.000 to 999.999 and then recycles back to zero. The 1/1000 mile position is not normally displayed unless the computer was directed to do so during the power on customization. You may also temporarily view the 1/1000 mile (and time) by pressing the ENT button while in the RUN mode. (Press ENT again to resume normal display)
To set the odometer to a predetermined value, move the function selector to the 0D0 position. Note that their are up to six digits in the odometer display but only 4 up/down set positions! The 1/1000 mile position is set using the SEL key, and the 100 miles position is set by rolling the 10 miles position past it's end. This procedure is very easy to understand once you've tried it a few times. The best way to learn to use your ALFA-tsd is to play with it and explore it's various functions to see the effect they have on the computed values.
Once you have dialed up the value desired, press the ENT key to transfer the value to the odometer. Once the ENT key is pressed, the keyboard is locked out to prevent accidental entries (this is indicated by the prompt changing to all capital letters). If you need to re-enter the value, simply move the function switch one position in either direction and then back again. This action will clear the keyboard and allow another entry.
To adjust the odometer by a small increment, rotate the function knob to the +/-D position (Add/Subtract Distance). You may then add or subtract in either .01 or .001 mile increments (determined by customization). Use the SEL key to switch between add or subtract. During the +/-D operation, computed time is not effected.
You may adjust the odometer and simultaneously adjust computed time by a corresponding amount using the +/-DT mode. This is the same as the +/-D function, except the computed time is adjusted at the active CAS. This feature is handy to use for correcting distance error at checkpoint lines, and generally correcting the computer during course following.
If you selected the "Clear on Enter" mode of operation, the value for +/-D, +/-DT, and +/-T functions will return to zero after you enter them. Normally the value remains where ever it was last set.
The navigator may set a mileage at which some action needs to be taken by using the ALARM function. You enter the alarm distance in the same manner as the main odometer preset. Once entered, the ALFA-tsd will compute the difference between the current course mileage and the alarm setting and display the difference on the driver's odometer. This value will effectively count backwards to zero as you approach the alarm setting. The CAS indicator in both the driver's and navigator's displays will blink the word "BEEP" when you come within .2 miles of the alarm setting (Optional beeper will sound if installed). To cancel the alarm at any time, select the ALARM or RUN position on the function knob, and press CLR.
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An odometer correction factor is available so that you can match your mileage to the rallymaster's, and thereby obtain more precise distance and time information for the rally. The factor is viewed and set by rotating the function knob to the FACT position. The message displayed will be either FACTOR A or FACTOR B depending upon the position of the A/B switch on the side of the computer. This allows you to have either two different sending units with their correct factors preprogrammed, or allows you to have two preprogrammed factors for your single sending unit. Use the SEL button to switch between the active and inactive factor. In the FACTOR mode, the CLR button increments the rightmost (least significant) digit of the factor.
The value of the factor is the fraction of a mile traveled between sending unit pulses (usually two pulses for each rotation of the wheel). The factor is set to 50000 (5000 prior to revision 3 software) when you initially apply power to the computer (if non-volitile memory is installed, the last factor used is retained). This corresponds to .00050000 miles (2.64 feet) between pulses. If your odometer comes up short at mileage references, you need to increase the factor. If your odometer runs long at references, decrease the factor. Most rallies provide an odometer check leg in order for rallyists to determine their factor. There is an easy formula for determining your factor at the end of an odometer leg: The new factor is equal to the current factor divided by the distance recorded multiplied by the actual distance in the route instructions.
Example: You start the odometer leg with a factor of 50000. The end of odometer leg is officially 12.56 miles, but your ALFA-tsd says 11.21 miles. 50000 divided by 11.21 times 12.56 is 56021. 56021 is your new factor and should be programmed into the factor for the sending unit used to run the check. If you went back and re-ran the odometer check, your mileage should come out exactly correct at every reference point.
Beginning with revision 3 software, the ALFA-tsd can calculate it's own factor. When you begin the odometer check leg, be sure to set your odometer to 000.000 miles. At the end of the odometer check (do not make any odometer changes during the odometer check leg) stop your car adjacent to the final reference point. Move the function knob to the ODO position, dial up the correct mileage for the reference point, and press ENT. BEFORE rotating the function knob again, press the SEL button; the new factor is now being calculated (this may take from a few seconds to a minute). Once the calculation is complete a message appears, and you may now move the function knob to the FACT position. The calculated factor will now appear in place of the factor you were using. If you wish to use the calculated factor, simply press ENT. You may discard the calculated factor and enter your own factor by simply rotating the function knob to a different position and back to FACT again.
The Forward/Reverse switch causes the odometer and computed time to run forward or backward. The Park position effectively disconnects the sending unit from the computer, freezing the odo and ctc (the real time clock is unaffected). To recover from an off course excursion, park the odometer at a known reference point (tree, sign, etc..) and turn the car around. As you pass the reference point in the reverse direction, move the switch to the Reverse position. The odometer will now count backwards as you retrace your steps. When you arrive at the point where you made your mistake, repeat the procedure except this time move the switch to the forward position to follow the correct course. Your odometer and computed time will be correct from this point on (but you will be very late and must now either make up the time by driving above CAS or taking a time allowance!). Note: If you are used to using some other rally computers, the forward and reverse functions did not work with a high degree of precision (drive one mile, reverse the box and drive back and the mileage doesn't match exactly!). This was due to the method of factoring the odometer as well as several other points. The ALFA-tsd has corrected these inaccuracies and the only discrepancies you will find in off-course recovery is that you are riding on the opposite side of the road so the distance traveled around curves will be different. Some practice will allow you to recover almost perfectly from off-course excursions.
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The ALFA-tsd allows you to enter your CAS changes in advance. To enter an advance CAS, move the function selector to the CAS position, and dial in the desired value (00.01 to 99.99 mph). When the desired CAS is dialed in, press ENT, this value is now your NEXT CAS. Note that setting the NEXT CAS value has no effect on the ACTIVE CAS no matter how many times you set or reset the value.
To change the CAS value being used by the ALFA-tsd (the active CAS), simply press the CAS key. The CAS key will move the NEXT CAS to the ACTIVE CAS, and immediately begin calculating with the new value. The CAS key is functional regardless of the position of the function knob or the hold button so that you cannot miss a CAS change because you were doing something else at the time.
It is a good idea to program the NEXT CAS into the computer as soon as you change to a new ACTIVE CAS so that you won't forget and have to do it in a panic. All of the data entry features of your new ALFA-tsd were designed to allow advance operation and therefore reduce navigational errors.
If you forgot to enter next CAS, or the correct CAS is not known until the reference point occurs, the ALFA-tsd can accommodate you. As you pass the reference point, press the CAS button even though the next CAS is incorrect. (The ALFA records each CAS change, and can recalculate from the current position back to the previous CAS) At your convenience, rotate the function knob to the CAS position, and enter the CAS you should have switched to. After pressing ENT, press the SEL button (before moving the function knob) and the leg will be recalculated and the ACTIVE CAS will be correct. (Note that the longer the distance since the last CAS change, the longer it will take to recalculate. There is no need to stop the car during a recalculation, although the displays will freeze while it is going on.)
Entering a CAS of 00.00 mph in the ALFA-tsd parks the CTC while allowing the odometer to continue running. This is useful for transit zones where a time is given over a distance rather than a CAS. At the start of the transit zone set your CAS to 00.00 and enter a pause (+/- T position) for the amount of time you have to complete the transit zone. The drivers NULL display now shows the amount of time remaining to complete the transit zone. When you arrive at the end of the transit zone, simply change your CAS back to the correct value and keep on driving, the NULL will be correct automatically!
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The Real-Time Clock usually only needs to be set once at the beginning of the rally. To set the clock, move the function knob to the RTC position and dial the time that you would like to set (usually the next whole minute). Watch the official clock, and press the ENT and LOWER LEFT ARROW key together at exactly the time you wanted to set. The clock will now start running normally. (Note that as a safety precaution, you must press two buttons together to set the clock! We have discovered that the easiest way to do this is to press and hold the ENT key a few seconds before your "hack" and strike the ARROW key at the hack while still holding the ENT key, then release them both).
When setting the clocks, note that only the leftmost three up/down switches function for hours, minutes, and hundredths (seconds) respectively. The CLR key only sets the hundredths (seconds) to zero. When the clock is started, all undisplayed digits are set to zero for maximum accuracy.
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Set the Computed-Time Clock (CTC) in the same manner as the RTC except that the function knob is in the CTC position and you only need to press ENT (no safety is provided for CTC). The CTC is normally set at each restart time, and then is updated by the computer along with the odometer. The SEL key will force the time setting function to the current value of the CTC or RTC which reduces the amount of button pressing required to set the clock.
During the course of a rally you sometimes need to PAUSE (Add Time) or GAIN (Subtract Time). The +/- T function accomplishes this by adding or subtracting the required number of hundredths (or seconds) to the CTC. The SEL key selects PAUSE or GAIN and the display will reflect the desired function. The CLR key sets the value to ZERO. It is important to note that when the timing is set to run in seconds the +/-T value is in seconds, not minutes and seconds! To pause one minute, you must program a pause of 60 seconds, two minutes are 120 seconds and so on. The maximum pause is 9999 seconds (about 2.77 hours!). When the timing is in hundredths, the pause value takes on the effect of minutes and hundredths due to the decimal nature of that timing system (one minute is 100 hundredths, two minutes is 200 hundredths etc., maximum pause in hundredths is 999, or about an hour and a half!). Note that due the internal calculations which are performed during a pause (or gain) of more than 10 minutes, allow a few seconds for the pause to be entered before the display updates. This delay HAS NO EFFECT on either the odometer, CTC or other calculations.
If you selected the "Clear on Enter" mode of operation, the value for +/-D, +/-DT, and +/-T functions will return to zero after you enter them. Normally the value remains where ever it was last set.
Your ALFA-tsd keeps a log of all CAS changes, Pause/Gains, or CTC sets. This allows you to review your performance or correct course or scoring errors. The last 32 operations are stored in the log, with the oldest being discarded as new operations are entered. To review the log, rotate the function knob to the LOG position (fully counter clockwise on units without LOG labels on the panel). You may use the leftmost up and down arrows to view one item at a time. The logged items are numbered, with #1 being the most recent. Press CLR to reset the log. (Note that the log simply stores whatever was on the display, therefore if the display is held or in some other odd mode the log entry may be garbled. Logged mileages include 1/1000 miles regardless of customization.)
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Appendix A - Differences between Elite and TSD computers:
Beginning in August 1992, an improved version of the ALFA-tsd called the AFLA-Elite was created. The software features of the Elite are identical to the TSD except in the following details:
1: The CAS change button has been moved to the upper left corner of the box, and made larger.
2: The HOLD switch is now a toggle switch rather than a push button, and has been relocated to the upper right corner of the box.
3: A larger keyboard is used.
4: The keyboard position formerly occupied by the CAS button, is now a .001 button. This button operates the
thousandths digit in all entry modes, freeing the CLR and SEL buttons for their normal use.
5: When setting the odometer, the SEL button will set the current odometer value onto the screen, as in the CTC and RTC modes.
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Appendix B - Care and Feeding of Liquid Crystal Displays:
Liquid crystal displays have many advantages over conventional LED or Incandescent displays. Several safeguards must be observed however to insure the proper operation and life of the display.
LCD's do not like extreme temperature! If the display is too cold, contrast will be reduced (less than 30 degrees F), if too hot, the display will turn black (greater than 135 degrees F). Dashboard temperatures can reach 180-200 degrees on a hot day with the car parked in the sun with the windows closed! If you leave your car parked in the sun, leave several windows open a crack. If the displays turn black, they will return to normal after several minutes of driving around when the temperature drops. The manufacturer of these displays says that they will not be permanently damaged by turning black, and our experience confirms this fact. The computer will continue to operate, even if the displays black out from heat. It is a good idea to cover your computer with a white cloth (T-shirt or diaper is perfect) when left alone in the sun, this seems to prevent all but the most extreme problems. A sunshade attached to your ALFA-tsd will also work to prevent these problems. The general rule is: If you are comfortable, the LCD is comfortable.
LCD displays are made of glass. If the glass breaks, do not touch the liquid which will leak from it. It is toxic! The front panel of your ALFA is made of Lexan, and will protect you from any broken glass.
The contrast control may need to be readjusted from time to time as the temperature and ambient lighting conditions in your car change. This is normal. The Electro-Luminescent lamp may be useful during day operation in heavily shadowed conditions (What, trees on a rally road!). (ALFA computers manufactured since 1992 use LED backlighting which does not have an on/off switch)
Be careful when adjusting the contrast control so that you do not interrupt the power to the unit accidentally!
Small Systems Specialists recommends removing the ALFA-tsd from your car when it is not in use. This prevents both theft and premature aging!
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Appendix C - Software revision history:
Revision 1:
A star is born
Revision 2:
RTC safety (ENT & Arrow)
Speedometer on drivers display
ENTER key toggle for 1/1000 ths
Null thousandths and graphic display
Log feature
Performance computer
Modified PARK and REVERSE indicators
Revision 3:
Non-volitile memory
Customize at any time (lower corners together)
Operation without drivers display
6 digit odometer factor
Beeper support (beeps in reverse, park and alarm)
Last CAS recalc
Last HOLD recall
Factor calc
Numbered log entries
Set +/-DT and CTC in thousandths
SEL key to grab current CTC, RTC and ODO
Eliminate performance computeR
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Warranty:
Your ALFA-tsd is warranted against defects in materials and workmanship for a period of one year from the date of purchase. This warranty does not cover any parts broken due to abuse, neglect, or misuse of this product as determined by Small Systems Specialists.
The liquid crystal display is warranted against electrical failure for one year, but not against breakage of the glass.
This warranty is void if the case is found to have been opened or Small Systems Specialists or it's agents discovers any evidence of tampering.
Although every effort has been made to ensure reliable, accurate operation, Small Systems Specialists will not be responsible for any loss of money, property, time or trophies due to the malfunction of this product. Good operating practice dictates that the user verify that the product is in good working order before it is relied upon during competition.
The ALFA-tsd and other clocks may require periodic calibration. This function may be performed for the cost of shipping only at any time during the ownership or use of this product.
In the event that your ALFA-tsd changes ownership, any warranties or other coverage will still be honored as long as the new owner registers ownership with Small Systems Specialists within 30 days of receiving the product.
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ALFA Rally products are built in the USA by the rallyists at:
Small Systems Specialists
PO Box 310
Windsor, NJ 08561
Phone 609-426-0541, Fax 734-661-4039
Email to: ALFA@Rally.cc
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